Photograph by Joel Sartore, National Geographic Photo Ark
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Larval antlions, like this one at Cedar Point Biological Station, are as scary a predator as they appear.
Photograph by Joel Sartore, National Geographic Photo Ark

Neither cute nor cuddly: These animal babies are wee monsters

Unlike the usual roundup of adorable critters, these little shape shifters, cannibals, and body snatchers will haunt your Halloween.

Human kids dress up as monsters for Halloween, but some animal babies are a lot like the real thing.

Of course, they’re just doing what comes naturally, but that doesn’t mean it isn’t creepy. So this week we asked, which animal babies are not the cute and cuddly type?

Spadefoot toad tadpoles

Some spadefoot tadpoles of the eastern U.S. begin life as omnivores, eating plant matter like algae and detritus in the sand — until they get nice big bite of the flesh of another species of spadefoot tadpole. Then, they change.

These tadpoles become what’s known as a carnivore morph, “a much bigger tadpole” with “much bigger mouthparts,” says Greg Pauly, curator of herpetology at the Natural History Museum of Los Angeles County.

This carnivorous youngster eschews plants and sticks to fairy shrimp, its toad cousins, and sometimes its own species.

Caecilians

Caecilians are legless, burrowing amphibians, the young of which eat parts of their mother alive.

Mom grows an outer layer of fatty skin meant for the babies to peel off and eat with specialized teeth. It’s a bit like when a lizard, or a tanning enthusiast, sheds its skin. It’s not so different, Pauly says, from “other mammals that are suckling their young,” transitioning nutrients from their own body to their babies.

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A mother caecilian grows a special layer of skin that is her kid's first meal. This yellow-striped caecilian, a legless amphibian, is at the San Antonio Zoo.

Paradoxical frogs

The paradoxical frog tadpole isn’t vicious, but it is a giant, around ten inches long. And yet, the adult frogs isn’t much more than three inches.

How does a monster-sized baby shrink?

Most of the tadpole is tail, which provides the energy to fuel this “massive transformation,” Pauley says, from tadpole to frog.

Human botfly

This Central and South American species doesn’t even have to get close to us in order to plant its kids right under our skin.

The adult botfly attaches its eggs to a mosquito. When the mosquito bites a human, the person’s body heat triggers the eggs to hatch and the larvae burrow under the skin.

Then, the larvae feed on our white blood cells — though not enough to do any harm, says Gil Wizen, an entomologist at the Royal Ontario Museum in Toronto.

Wizen has allowed his own body to serve as a botfly nursery twice. He says their entry and departure isn’t even noticeable because “they secrete some chemicals to numb the whole area.”

Watch a Hercules Beetle Metamorphose Before Your Eyes May 11, 2018 - Watch this beetle go from larvae to giant. The Hercules beetle is one of the largest flying insects in the world. As beetle expert Brett Ratcliffe puts it, they “are basically the size of a Polish sausage.”

He was determined to see the ‘birth’ of the second adult fly though.

“It’s a beautiful fly, and not because it’s my son,” he says. In fairness, this metallic blue-bodied bug is pretty eye-catching.

We hope that’s not where anyone catches it.

Antlion

Antlion larvae are pretty fierce looking little ones, but their method of trapping prey is like something straight out of a scary movie. They dig pits in soft sand, so when a poor ant happens by and loses its footing, it can’t climb out and falls into the pit.

If the ant struggles, the antlion is there to throw sand and stones on it so that it just can’t make it out. Eventually, the ant ends up in the curved, serrated, hollow jaws of the young antlion, which sucks the life out of them.

These insects live in the eastern U.S., so if you live in that region and see little pits in your yard, there may be more drama going on underfoot than you realize.

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The larvae of the ground beetle (Epomis circumscriptus, adult (right) and larva shown) suck the blood and tissue from frogs.

 

And from this ferocious little one grows a very pretty insect, which looks much like a delicate dragonfly.

Ground beetle larvae

This bug eats frogs, instead of the other way around.

Two species of ground beetle larvae lure frogs by wiggling their antennae, making themselves look like prey. When the frog gets close enough, “they strike,” says Wizen, who described this behavior in a 2011 study in the journal PLoS One.

The larvae will attach to the first body part they can; if that happens to be the tongue that almost caught them, they may move around to the throat so they don't get chomped. They can relocate to a better spot using “a sewing movement” of their hooked jaws, Wizen says.

The larvae will suck blood and soft tissue out of the frog for about a week, then “start chewing until nothing is left” but bone, Wizen says.

Sounds horrible, but since frogs eat untold numbers of insects in a lifetime, Wizen asks, “Who’s the real evil here?”

In the end, it’s not evil, it’s just nature.

Have a question about the weird and wild world? Tweet me, leave me a note in the comments, or find me on Facebook. Weird Animal Question of the Week answers your questions every Friday.